1. Field of the Invention
This invention relates generally to orthodontic appliances, and more specifically to an improved overbite and underbite corrective device.
2. Description of the Prior Art
Numerous orthodontic appliances have been developed to treat malocclusions of the upper and lower jaw. For example, Armstrong U.S. Pat. No. 3,618,214 discloses a coiled wire appliance utilizing small springs inside plastic tubes to pull the jaws together. More recently, Jasper U.S. Pat. No. 4,708,646 teaches the use of one or more flexible members which are attached at opposite ends to the upper and lower jaws of a patient. The end attachments allow the members to swivel freely and the members to bend when the patient is chewing, talking, or cleaning his or her teeth, but when the patient is relaxed, the members tend to straighten and apply a small but continuous force generally along the normal growth direction for a human jaw to overcome the abnormality being treated. However, these flexible members are specifically non-stretching, which limits their use in certain corrective applications. In addition, the Jasper appliance is not adjustable in length, necessitating a variety of sizes to fit different users. Furthermore, the Jasper device is often difficult to install in a patient's mouth, and is prone to breakage.